Jens Axboe abdad709ed io_uring: recycle provided before arming poll
We currently have a race where we recycle the selected buffer if poll
returns IO_APOLL_OK. But that's too late, as the poll could already be
triggering or have triggered. If that race happens, then we're putting a
buffer that's already being used.

Fix this by recycling before we arm poll. This does mean that we'll
sometimes almost instantly re-select the buffer, but it's rare enough in
testing that it should not pose a performance issue.

Fixes: b1c6264575 ("io_uring: recycle provided buffers if request goes async")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-03-20 07:23:57 -06:00
2022-03-06 14:28:31 -08:00

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